Process for alkoxylating a mixture of methyl glucoside and a hydroxy compound, and the product of that process



United States Patent PROCESS FOR ALKOXYLATING A MIXTURE F METHYLGLUCQSIDE AND A HYDROXY COM- POUND, AND THE PRODUCT OF THAT PRGCESSDonald W. Kaiser and Stephen Fuzesi, Hamden, Conn, assignors to OlinMathieson Chemical Corporation, a corporation of Virginia No Drawing.Filed May 24, 1962, Ser. No. 197,245

9 Claims. (Cl. 260210) The present invention relates to a novel processfor the alkoxylation of methyl glucoside and to the improved productresulting from said process. I

Methyl glucoside is derived from corn starch and is commerciallyavailable at a reasonable price competitive with industrial polyols. Theproduct is a stable mixed acetal of glucose and methyl alcoholcontaining four hydroxyl groups. The hydroxyl groups are capable ofpolyetherification with an alkylene oxide, especially ethylene orpropylene oxide, to yield appropriate derivatives for subsequent crosslinking with diisocyanates to form polyurethane foams.

Methyl glucoside is a relatively high melting solid which melts at 168to 169 C. when pure. The solid methyl glucoside must be transformed tothe molten state in order to be reacted with an alkylene oxide in thepresence of a basic catalyst to form the methyl glucoside polyethersuseful in the preparation of the polyurethane foams. A disadvantage ofthe use of methyl glucoside in the preparation of methyl glucosidepolyethers is that high temperature alkoxylation tends to produceundesirable color. Furthermore, when methyl glucoside is alkoxylated tothe desired hydroxyl number for use in rigid polyurethane foams, theresultant alkoxylated methyl glucoside is too viscous for convenienthandling and reaction.

It is, therefore, an object of the present invention to provide a novelprocess for the preparation of alkoxylated methyl glucoside.

It is a further object of the present invention to provide a novelalkoxylated methyl glucoside product.

It is a still further object of the present invention to provide aprocess as above which avoids the art disadvantage of undesirable colorformation.

It is a still further object to provide a process as above which iscapable of preparing alkoxylated methyl glucoside for use in rigidpolyurethane foams without the disadvantage of high viscosity.

Further objects and advantages of the present invention will appearhereinafter.

In accordance with the process of the present invention it has now beenfound that the foregoing objects and advantages may be accomplished anda novel alkoxylated methyl glucoside product prepared by: admixingmethyl glucoside with a hydroxy compound in a molar ratio of methylglucoside to hydroxy compound of between 1:0.1 and 1:10, said hydroxycompound being selected from the group consisting of a polyhydricalcohol containing at least three hydroxyl groups and an aminohydroxycompound with a functionality of at least three, in the presence of abasic catalyst; maintaining the mixture at a temperature of from 100 to165 C. and introducing into said mixture an alkylene oxide.

It has been found, surprisingly and unexpectedly, that ice when apolyhydric alcohol containing at least three hydroxyl groups or anaminohydroxy compound with a functionality of at least three, is admixedwith the methyl glucoside in the alkoxylation reaction, thedisadvantages of the art are overcome and the resultant alkoxylatedproduct is unhindered by undesirable color formation and high viscosity.In addition, the liquid polyol, such as glycerol, provides the solventaction for the methyl glucoside. The resultant alkoxylated product isactually a coalkoxylated product, i.e., the alkylene oxide reacts withboth the methyl glucoside and the polyhydric alcohol or aminohydroxycompound, thus providing the desirable characteristics of each.

The products of the present invention may be readily cross-linked withdiisocyanates to form polyurethane foams having excellent physicalproperties.

In the process of the present invention any polyhydric alcoholcontaining at least three hydroxyl groups may be employed, with thepreferred polyhydric alcohols being glycerol, pentaerythritol andpolypentaerythritol. The polyhydric alcohol may be aromatic oraliphatic. Other polyhydric alcohols which may be conveniently employedinclude the following: sorbitol, hexanetriol, trimethylol propane,anhydroenneaheptitol, pyrogallol, etc. Any aminohydroxy compound with afunctionality of at least three may be employed, for example, mono-,dior triethanolamine.

The alkoxylation reaction is accelerated by employing elevatedtemperatures, i.e., from to 165 C. and the use of a basic catalyst, suchas the conventional organic or inorganic base activators, preferably analkali metal hydroxide, alkali metal alkoxide or tertiary amine, such assodium hydroxide, potassium hydroxide, sodium alkoxide, sodiummethylate, triethyl amine, and the like. The use of elevatedtemperatures and basic catalysts is conventional in the alkoxylationart. Proper use of these will be apparent to one skilled in the art. Thecatalyst is generally employed in an amount of between about 1 to 5percent by weight of the polyol. The reaction is initially exothermicand cooling means are employed in order to maintain the reaction at thedesired temperature.

In the foregoing reaction any alkylene oxide may be employed andpreferably the lower alkylene oxides, such as ethylene or propyleneoxide. Others which may be employed include, for example, butyleneoxide, isobutylene oxide, N-hexyl oxide, etc.

In general, the basic catalyst is neutralized with a mineral acid, suchas phosphoric, sulfuric or hydrochloric. The resultant product is alight colored liquid.

The process of the present invention will be more readily apparent froma consideration of the following illustrative examples.

EXAMPLE 1 A mixture of 388 grams (2.0 moles) of methyl glucoside, 23grams (0.25 mole) of glycerol, and 8 grams of 85 percent potassiumhydrom'de was stirred and heated under nitrogen. At C. the mixture wasmolten. In this instance, the temperature was raised to C. andpropoxylation carried out until 743 grams of propylene oxide had beenreacted. When cool, the mixture was neutralized with 50 percent sulfuricacid, treated with 35 grams of Attapulgus clay and then stripped for anhour 3 at 120 C./5 mm. before filtration. Analysis of the light yellowliquid gave the following values:

. i 1.1 grams of triethylenediamine 74.0 grams of a mixture of tolylenediisocyanate.

Hxdroxyl number 435 The mixture was allowed to foam and was cured atele- Acld number 0.17 t d h 1 1 h L Percent water 04 va e temperature. Te resu tant Ilgld po yurct ane roam Apparent PH was whlte 1n color, hadan excellent cell structure and Vi i 100 F "CS" 4 539 excellent P Y P PTh1s invention may be embodied in other forms or car- EXAMPLES 2 THROUGH6 ried out in other ways without departing from the spirit In thefollowing examples th procedure of E l or essential characteristicsthereof. The present embodi- 1 was repeated except that the molar ti ofth l lument is therefore to be considered as in all respects illuscosideto glycerol is as shown in the following table. trative and notrestrictive, the scope of the invention being Table 1 Molar RatioViscosity Example Methyl Hydroxyl Acid Percent Apparent 100F. ColorNumber tGlllcOsldel Number Number Water pH Centistokes 0 ycero 4 a at 3a2-? at 4111111111111: 4E1 301 0102 0.16 717 1, 384 D8: 5 8:1 435 0. 170. 04 5. 75 4, 539 Do. 6 4:1 414 0. 07 0. 05 6.1 Do.

1 Alkaline Number.

EXAMPLE 7 indicated by the appended claims and all changes which A rigidpolyurethane foam was prepared from the prodi g g the f range ofequivalency are not of Example 4 by admixing the following ingredients:1 33 1 55 2 53 me 100 grams of the liquid product of Example 4 1. Aprocess for the alkoxylation of a mixture of meth- 25 grams of tl'lflllro h r m yl glucoside and a hydroxy compound which comprises gram ostannous octoate admixing methyl glucoside with a hydroxy compound ingram of l1'1ethy1eI 1ed1am1ne a molar ratio of methyl glucoside to saidhydroxy com- 64.6 grams of a m1xture of lsomers of tolylene dnsopound ofbetween :0 and 1:1 Said hydroxy cyanate pound being selected from thegroup consisting of glycerol, The mixture was allowed to foam and wascured at elepentaerythritol, polypentaerythritol, sorbitol, hexanetriol,vated temperature. The resultant rigid polyurethane foam trimethylolpropane, .anhydroenneaheptitol, pyrogallol, Was White in had anExcellent 0611 Structure a monoethanolamine, diethanolamine, andtriethanolamine, cellent physical properties. in the presence of a basiccatalyst, maintaining the mix- EXAMPLE 8 ture at a temperature of from100 to 165 C., and introducing into said mixture an alkylene oxidehaving beig f 1 ig repeated f 2 i exgepncon 3 tween 2 and about 6 carbonatoms. me y g.ucosl e was propoxy a e m e a e 2. A process according toclaim 1 wherein said alkylene polyhydrrc alcohol. The product was areddish-brown, o 1 highly viscous syrup having the following properties.0 g i gi g z z gz g to claim 1 Whersin Said Hydroxyl number: Viscosity100 F., centistokes drmliy compound is glycerin.

410 44,000 4. A process according to claim 1 wherein said hy- 425 droxycompound is pentaerythritol.

EXAMPLES 9 THROUGH 12 5O 5. The process according to claim 2 whereinsaid pol In the following examples the procedure of Examplehydnc'zlcohol z f l 2 ha I 1 was repeated except that pentaerythritolwas employed e acco? mg i f mm w Sal PO instead of glycerol. The methylglucoside was propoxyhydrlc 3160110115 Pentaerythmo lated until it was astirrable liquid at about 130 c., at The Product Produced by the Processof e which time the pentaerythritol was added. The results The PmductProduced y the Process i clafm 5- g are summarized in the followingtable. 9. The product produced by the process or claim 6.

Table 2 Molar Ratio Viscosity, Example Number Methyl I-Iydroxyl AcidPercent Apparent 100 P1, Color gltipositde Number Number Water pH i eltfiiitii 111 404 01 18 0. Amllggr. 22% 233 8:3? 8:11 716 are Do: 4:1 4500. 09. 0. 00 5.05 D0.

EXAMPLE 13 References Cited by the Examiner A rigid polyurethane foamwas prepared fromthe prod- UNITED STATES PATENTS not of Example 12 byadmixing the following ingredient 2,407,003 9 /46 Grimm g 100 grams ofthe liquid product of Example 12 3,042,666 7/ 62 Gentles 260-2 10 25grams of trifluorochloromethane I 0.2 gram of stannous octoate LEWISGOTTS, Primary Exammer.

1. A PROCESS FOR THE ALKOXYLATION OF A MIXTURE OF METHYL GLUCOSIDE AND AHYDROXY COMPOUND WHICH COMPRISES ADMIXING METHYL GLUCOSIDE WITH AHYDROXY COMPOUND IN A MOLAR RATIO OF METHYL GLUCOSIDE TO SAID HYDROXYCOMPOUND OF BETWEEN 1:0.1 AND 1:10, SAID HYDROXY COMPOUND BEING SELECTEDFROM THE GROUP CONSISTING OF GLYCEROL, PENTAERYTHRITOL,POLYPENTAERYTHRITOL, SORBITOL, HEXANETRIOL, TRIMETHYLOL PROPANE,ANHYDROENNEAHEPTITOL, PYROGALLOL, MONOETHANOLAMINE, DIETHANOLAMINE, ANDTRIETHANOLAMINE, IN THE PRESENCE OF A BASIC CATALYST, MAINTAINING THEMIXTURE AT A TEMPERATURE OF FROM 100 TO 165*C., AND INTRODUCING INTOSAID MIXTURE AN ALKYLENE OXIDE HAVING BETWEEN 2 AND ABOUT 6 CARBONATOMS.